aboutsummaryrefslogtreecommitdiff
path: root/drivers/pci/pci-driver.c
blob: 39e80fcef4b343a9704179665aab52ba4e3271e7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
/*
 * drivers/pci/pci-driver.c
 *
 */

#include <linux/pci.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/mempolicy.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include "pci.h"

/*
 *  Registration of PCI drivers and handling of hot-pluggable devices.
 */

/* multithreaded probe logic */
static int pci_multithread_probe =
#ifdef CONFIG_PCI_MULTITHREAD_PROBE
	1;
#else
	0;
#endif
__module_param_call("", pci_multithread_probe, param_set_bool, param_get_bool, &pci_multithread_probe, 0644);


/*
 * Dynamic device IDs are disabled for !CONFIG_HOTPLUG
 */

struct pci_dynid {
	struct list_head node;
	struct pci_device_id id;
};

#ifdef CONFIG_HOTPLUG

/**
 * store_new_id - add a new PCI device ID to this driver and re-probe devices
 * @driver: target device driver
 * @buf: buffer for scanning device ID data
 * @count: input size
 *
 * Adds a new dynamic pci device ID to this driver,
 * and causes the driver to probe for all devices again.
 */
static ssize_t
store_new_id(struct device_driver *driver, const char *buf, size_t count)
{
	struct pci_dynid *dynid;
	struct pci_driver *pdrv = to_pci_driver(driver);
	__u32 vendor=PCI_ANY_ID, device=PCI_ANY_ID, subvendor=PCI_ANY_ID,
		subdevice=PCI_ANY_ID, class=0, class_mask=0;
	unsigned long driver_data=0;
	int fields=0;
	int retval = 0;

	fields = sscanf(buf, "%x %x %x %x %x %x %lux",
			&vendor, &device, &subvendor, &subdevice,
			&class, &class_mask, &driver_data);
	if (fields < 0)
		return -EINVAL;

	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
	if (!dynid)
		return -ENOMEM;

	INIT_LIST_HEAD(&dynid->node);
	dynid->id.vendor = vendor;
	dynid->id.device = device;
	dynid->id.subvendor = subvendor;
	dynid->id.subdevice = subdevice;
	dynid->id.class = class;
	dynid->id.class_mask = class_mask;
	dynid->id.driver_data = pdrv->dynids.use_driver_data ?
		driver_data : 0UL;

	spin_lock(&pdrv->dynids.lock);
	list_add_tail(&pdrv->dynids.list, &dynid->node);
	spin_unlock(&pdrv->dynids.lock);

	if (get_driver(&pdrv->driver)) {
		retval = driver_attach(&pdrv->driver);
		put_driver(&pdrv->driver);
	}

	if (retval)
		return retval;
	return count;
}
static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);

static void
pci_free_dynids(struct pci_driver *drv)
{
	struct pci_dynid *dynid, *n;

	spin_lock(&drv->dynids.lock);
	list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
		list_del(&dynid->node);
		kfree(dynid);
	}
	spin_unlock(&drv->dynids.lock);
}

static int
pci_create_newid_file(struct pci_driver *drv)
{
	int error = 0;
	if (drv->probe != NULL)
		error = sysfs_create_file(&drv->driver.kobj,
					  &driver_attr_new_id.attr);
	return error;
}

#else /* !CONFIG_HOTPLUG */
static inline void pci_free_dynids(struct pci_driver *drv) {}
static inline int pci_create_newid_file(struct pci_driver *drv)
{
	return 0;
}
#endif

/**
 * pci_match_id - See if a pci device matches a given pci_id table
 * @ids: array of PCI device id structures to search in
 * @dev: the PCI device structure to match against.
 *
 * Used by a driver to check whether a PCI device present in the
 * system is in its list of supported devices.  Returns the matching
 * pci_device_id structure or %NULL if there is no match.
 *
 * Depreciated, don't use this as it will not catch any dynamic ids
 * that a driver might want to check for.
 */
const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
					 struct pci_dev *dev)
{
	if (ids) {
		while (ids->vendor || ids->subvendor || ids->class_mask) {
			if (pci_match_one_device(ids, dev))
				return ids;
			ids++;
		}
	}
	return NULL;
}

/**
 * pci_match_device - Tell if a PCI device structure has a matching PCI device id structure
 * @drv: the PCI driver to match against
 * @dev: the PCI device structure to match against
 *
 * Used by a driver to check whether a PCI device present in the
 * system is in its list of supported devices.  Returns the matching
 * pci_device_id structure or %NULL if there is no match.
 */
const struct pci_device_id *pci_match_device(struct pci_driver *drv,
					     struct pci_dev *dev)
{
	struct pci_dynid *dynid;

	/* Look at the dynamic ids first, before the static ones */
	spin_lock(&drv->dynids.lock);
	list_for_each_entry(dynid, &drv->dynids.list, node) {
		if (pci_match_one_device(&dynid->id, dev)) {
			spin_unlock(&drv->dynids.lock);
			return &dynid->id;
		}
	}
	spin_unlock(&drv->dynids.lock);

	return pci_match_id(drv->id_table, dev);
}

static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
			  const struct pci_device_id *id)
{
	int error;
#ifdef CONFIG_NUMA
	/* Execute driver initialization on node where the
	   device's bus is attached to.  This way the driver likely
	   allocates its local memory on the right node without
	   any need to change it. */
	struct mempolicy *oldpol;
	cpumask_t oldmask = current->cpus_allowed;
	int node = pcibus_to_node(dev->bus);
	if (node >= 0 && node_online(node))
	    set_cpus_allowed(current, node_to_cpumask(node));
	/* And set default memory allocation policy */
	oldpol = current->mempolicy;
	current->mempolicy = &default_policy;
	mpol_get(current->mempolicy);
#endif
	error = drv->probe(dev, id);
#ifdef CONFIG_NUMA
	set_cpus_allowed(current, oldmask);
	mpol_free(current->mempolicy);
	current->mempolicy = oldpol;
#endif
	return error;
}

/**
 * __pci_device_probe()
 * @drv: driver to call to check if it wants the PCI device
 * @pci_dev: PCI device being probed
 * 
 * returns 0 on success, else error.
 * side-effect: pci_dev->driver is set to drv when drv claims pci_dev.
 */
static int
__pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev)
{
	const struct pci_device_id *id;
	int error = 0;

	if (!pci_dev->driver && drv->probe) {
		error = -ENODEV;

		id = pci_match_device(drv, pci_dev);
		if (id)
			error = pci_call_probe(drv, pci_dev, id);
		if (error >= 0) {
			pci_dev->driver = drv;
			error = 0;
		}
	}
	return error;
}

static int pci_device_probe(struct device * dev)
{
	int error = 0;
	struct pci_driver *drv;
	struct pci_dev *pci_dev;

	drv = to_pci_driver(dev->driver);
	pci_dev = to_pci_dev(dev);
	pci_dev_get(pci_dev);
	error = __pci_device_probe(drv, pci_dev);
	if (error)
		pci_dev_put(pci_dev);

	return error;
}

static int pci_device_remove(struct device * dev)
{
	struct pci_dev * pci_dev = to_pci_dev(dev);
	struct pci_driver * drv = pci_dev->driver;

	if (drv) {
		if (drv->remove)
			drv->remove(pci_dev);
		pci_dev->driver = NULL;
	}

	/*
	 * If the device is still on, set the power state as "unknown",
	 * since it might change by the next time we load the driver.
	 */
	if (pci_dev->current_state == PCI_D0)
		pci_dev->current_state = PCI_UNKNOWN;

	/*
	 * We would love to complain here if pci_dev->is_enabled is set, that
	 * the driver should have called pci_disable_device(), but the
	 * unfortunate fact is there are too many odd BIOS and bridge setups
	 * that don't like drivers doing that all of the time.  
	 * Oh well, we can dream of sane hardware when we sleep, no matter how
	 * horrible the crap we have to deal with is when we are awake...
	 */

	pci_dev_put(pci_dev);
	return 0;
}

static int pci_device_suspend(struct device * dev, pm_message_t state)
{
	struct pci_dev * pci_dev = to_pci_dev(dev);
	struct pci_driver * drv = pci_dev->driver;
	int i = 0;

	if (drv && drv->suspend) {
		i = drv->suspend(pci_dev, state);
		suspend_report_result(drv->suspend, i);
	} else {
		pci_save_state(pci_dev);
		/*
		 * mark its power state as "unknown", since we don't know if
		 * e.g. the BIOS will change its device state when we suspend.
		 */
		if (pci_dev->current_state == PCI_D0)
			pci_dev->current_state = PCI_UNKNOWN;
	}
	return i;
}

static int pci_device_suspend_late(struct device * dev, pm_message_t state)
{
	struct pci_dev * pci_dev = to_pci_dev(dev);
	struct pci_driver * drv = pci_dev->driver;
	int i = 0;

	if (drv && drv->suspend_late) {
		i = drv->suspend_late(pci_dev, state);
		suspend_report_result(drv->suspend_late, i);
	}
	return i;
}

/*
 * Default resume method for devices that have no driver provided resume,
 * or not even a driver at all.
 */
static int pci_default_resume(struct pci_dev *pci_dev)
{
	int retval = 0;

	/* restore the PCI config space */
	pci_restore_state(pci_dev);
	/* if the device was enabled before suspend, reenable */
	retval = __pci_reenable_device(pci_dev);
	/* if the device was busmaster before the suspend, make it busmaster again */
	if (pci_dev->is_busmaster)
		pci_set_master(pci_dev);

	return retval;
}

static int pci_device_resume(struct device * dev)
{
	int error;
	struct pci_dev * pci_dev = to_pci_dev(dev);
	struct pci_driver * drv = pci_dev->driver;

	if (drv && drv->resume)
		error = drv->resume(pci_dev);
	else
		error = pci_default_resume(pci_dev);
	return error;
}

static int pci_device_resume_early(struct device * dev)
{
	int error = 0;
	struct pci_dev * pci_dev = to_pci_dev(dev);
	struct pci_driver * drv = pci_dev->driver;

	pci_fixup_device(pci_fixup_resume, pci_dev);

	if (drv && drv->resume_early)
		error = drv->resume_early(pci_dev);
	return error;
}

static void pci_device_shutdown(struct device *dev)
{
	struct pci_dev *pci_dev = to_pci_dev(dev);
	struct pci_driver *drv = pci_dev->driver;

	if (drv && drv->shutdown)
		drv->shutdown(pci_dev);
}

#define kobj_to_pci_driver(obj) container_of(obj, struct device_driver, kobj)
#define attr_to_driver_attribute(obj) container_of(obj, struct driver_attribute, attr)

static ssize_t
pci_driver_attr_show(struct kobject * kobj, struct attribute *attr, char *buf)
{
	struct device_driver *driver = kobj_to_pci_driver(kobj);
	struct driver_attribute *dattr = attr_to_driver_attribute(attr);
	ssize_t ret;

	if (!get_driver(driver))
		return -ENODEV;

	ret = dattr->show ? dattr->show(driver, buf) : -EIO;

	put_driver(driver);
	return ret;
}

static ssize_t
pci_driver_attr_store(struct kobject * kobj, struct attribute *attr,
		      const char *buf, size_t count)
{
	struct device_driver *driver = kobj_to_pci_driver(kobj);
	struct driver_attribute *dattr = attr_to_driver_attribute(attr);
	ssize_t ret;

	if (!get_driver(driver))
		return -ENODEV;

	ret = dattr->store ? dattr->store(driver, buf, count) : -EIO;

	put_driver(driver);
	return ret;
}

static struct sysfs_ops pci_driver_sysfs_ops = {
	.show = pci_driver_attr_show,
	.store = pci_driver_attr_store,
};
static struct kobj_type pci_driver_kobj_type = {
	.sysfs_ops = &pci_driver_sysfs_ops,
};

/**
 * __pci_register_driver - register a new pci driver
 * @drv: the driver structure to register
 * @owner: owner module of drv
 * @mod_name: module name string
 * 
 * Adds the driver structure to the list of registered drivers.
 * Returns a negative value on error, otherwise 0. 
 * If no error occurred, the driver remains registered even if 
 * no device was claimed during registration.
 */
int __pci_register_driver(struct pci_driver *drv, struct module *owner,
			  const char *mod_name)
{
	int error;

	/* initialize common driver fields */
	drv->driver.name = drv->name;
	drv->driver.bus = &pci_bus_type;
	drv->driver.owner = owner;
	drv->driver.mod_name = mod_name;
	drv->driver.kobj.ktype = &pci_driver_kobj_type;

	spin_lock_init(&drv->dynids.lock);
	INIT_LIST_HEAD(&drv->dynids.list);

	/* register with core */
	error = driver_register(&drv->driver);
	if (error)
		return error;

	error = pci_create_newid_file(drv);
	if (error)
		driver_unregister(&drv->driver);

	return error;
}

/**
 * pci_unregister_driver - unregister a pci driver
 * @drv: the driver structure to unregister
 * 
 * Deletes the driver structure from the list of registered PCI drivers,
 * gives it a chance to clean up by calling its remove() function for
 * each device it was responsible for, and marks those devices as
 * driverless.
 */

void
pci_unregister_driver(struct pci_driver *drv)
{
	driver_unregister(&drv->driver);
	pci_free_dynids(drv);
}

static struct pci_driver pci_compat_driver = {
	.name = "compat"
};

/**
 * pci_dev_driver - get the pci_driver of a device
 * @dev: the device to query
 *
 * Returns the appropriate pci_driver structure or %NULL if there is no 
 * registered driver for the device.
 */
struct pci_driver *
pci_dev_driver(const struct pci_dev *dev)
{
	if (dev->driver)
		return dev->driver;
	else {
		int i;
		for(i=0; i<=PCI_ROM_RESOURCE; i++)
			if (dev->resource[i].flags & IORESOURCE_BUSY)
				return &pci_compat_driver;
	}
	return NULL;
}

/**
 * pci_bus_match - Tell if a PCI device structure has a matching PCI device id structure
 * @dev: the PCI device structure to match against
 * @drv: the device driver to search for matching PCI device id structures
 * 
 * Used by a driver to check whether a PCI device present in the
 * system is in its list of supported devices. Returns the matching
 * pci_device_id structure or %NULL if there is no match.
 */
static int pci_bus_match(struct device *dev, struct device_driver *drv)
{
	struct pci_dev *pci_dev = to_pci_dev(dev);
	struct pci_driver *pci_drv = to_pci_driver(drv);
	const struct pci_device_id *found_id;

	found_id = pci_match_device(pci_drv, pci_dev);
	if (found_id)
		return 1;

	return 0;
}

/**
 * pci_dev_get - increments the reference count of the pci device structure
 * @dev: the device being referenced
 *
 * Each live reference to a device should be refcounted.
 *
 * Drivers for PCI devices should normally record such references in
 * their probe() methods, when they bind to a device, and release
 * them by calling pci_dev_put(), in their disconnect() methods.
 *
 * A pointer to the device with the incremented reference counter is returned.
 */
struct pci_dev *pci_dev_get(struct pci_dev *dev)
{
	if (dev)
		get_device(&dev->dev);
	return dev;
}

/**
 * pci_dev_put - release a use of the pci device structure
 * @dev: device that's been disconnected
 *
 * Must be called when a user of a device is finished with it.  When the last
 * user of the device calls this function, the memory of the device is freed.
 */
void pci_dev_put(struct pci_dev *dev)
{
	if (dev)
		put_device(&dev->dev);
}

#ifndef CONFIG_HOTPLUG
int pci_uevent(struct device *dev, char **envp, int num_envp,
	       char *buffer, int buffer_size)
{
	return -ENODEV;
}
#endif

struct bus_type pci_bus_type = {
	.name		= "pci",
	.match		= pci_bus_match,
	.uevent		= pci_uevent,
	.probe		= pci_device_probe,
	.remove		= pci_device_remove,
	.suspend	= pci_device_suspend,
	.suspend_late	= pci_device_suspend_late,
	.resume_early	= pci_device_resume_early,
	.resume		= pci_device_resume,
	.shutdown	= pci_device_shutdown,
	.dev_attrs	= pci_dev_attrs,
};

static int __init pci_driver_init(void)
{
	pci_bus_type.multithread_probe = pci_multithread_probe;
	return bus_register(&pci_bus_type);
}

postcore_initcall(pci_driver_init);

EXPORT_SYMBOL(pci_match_id);
EXPORT_SYMBOL(pci_match_device);
EXPORT_SYMBOL(__pci_register_driver);
EXPORT_SYMBOL(pci_unregister_driver);
EXPORT_SYMBOL(pci_dev_driver);
EXPORT_SYMBOL(pci_bus_type);
EXPORT_SYMBOL(pci_dev_get);
EXPORT_SYMBOL(pci_dev_put);